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UNITED STATES PATENT CEEICE.

OSBORN P. LOCMIS, OF SOMERVILLE, MASSACHUSETTS, ASSIGNCR TC THE IAOOMISELECTRIC MANUFACTURING COMPANY, OF NE\V YORK, N. Y.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 431,118, dated J' uly1, 1890.

Application tiled September 3, 1888. Serial No. 284,399. (No model.)

To all whom it may concern:

Ile it known that I, CSBORN P. LOOMIS, a citmen of the United States,residing at Somervllle, in the county of Middlesex and State ofMassachusetts, have invented certain neu7 and useful Improvements inElectric Switches, of which the following is such a full, clear, andexact description as will enable any one skilled in the art to which itappertains to make and use the same, reference being had to theaccompanying drawings, forming partof this specication. n My inventionrelates to an electric switch having' as a bridging means a pair ot'oppositely-arranged terminals, which engage with a spring-pressure thebridging-contact, which consists in a member with spring ends adapted to.engage the respective terminals with a spring-pressure, said contactingparts thereby exerting reciprocal spring-pressures; and, turther, theinvention relates to the peculiar manner ot operating the pivotedswitcharm, partly through means of the handle and partly through meansof a spring, and also in the novel arrangement of said spring, whichexerts its force on a dead-center when the pivoted switch-arm is in fullclosed position on the terminals, and serves to quickly t'orce theswitch open after the opening Inovement thereof has almost beencompleted through the manipulation of the handle.

The invention further relates to the novel and peculiar arrangements andconstructions ot' the several detail parts of the switch, all ashereinafter fully described and claimed.

The advantages peculiar to my improved switch are that firm and reliableconnection 1s secured between the terminals and the br1dging-contacts byVirtue of a reciprocal spring-pressure exerted therebetween, theContactin g surfaces are always kept clean and bright, and both sides orpoles of the circuit may be simultaneously opened and closed, and thatthe opening of the switch is not dependent upon the manipulation of thehandle after the initial movement has been given the same.

I have illustrated in the accompanying drawings, in which like numbersof reference designate like and corresponding parts throughout, adouble-pole electric switch constructed after the manner ot myinvention.

Figure l is a plan View of the switch in open position and with theinclosing-casing removed, the view being partly in section on a planeindicated by line l l, Fig. 2. Fig. 2 is a view similar to that inFig.l, but with the switch in closed position. Fig. 3 isa View of theswitch, together with its casing, in section on a plane indicated byline 3 3, lEig. 1, the lin e-terminals being omitted in this View. Fig.4 is a partial side view ot the right-hand side of Fig. 2.

Referring to the drawings, 6 designates a circular switch base orboard,which maybe made of Wood or any other suitable insulatingmaterial, and in a flat form, so that it may be conveniently attached toa plane surface. At the center of the base G is a pivot pin or post 7,provided with head 8 and secured in fixed position by means of suitablenuts and washers, though any other means of sustaining the post may beused. The switch-arm 9, preferably made of hard rubber, though anysuitable insulating material will answer, is

Vformed with a central eye, by means ot' which it is journaled on post7, so as to be movable in either direction thereon.

At each end of the switch-arm 9 is attached a bridging-contact l0,consisting in a metal plate or strip bent substantially U-shaped andhaving resilient ends. These contacts embrace in reverse manners therespective ends of the switch-arm, to which they are attached by meansof screws 1l, which are set through the arch of the U shape to allow thespring ends of the contacts to project free and to opposite sides of theswitch-arm. The ends of these contacts lookin opposite directionsrelatively to the length of the arm,which is limited in one direction ofits movement on its pivot by the stop l2, fixed in the base. A suitablewasher-plate is interposed between the arm and the base 6, so as topermit the flaring ends of the contacts l0 to clear the base as its armmoves on its pivot.

Correspondingly situated relatively to the pivotal point of theswitch-arm are the pairs of metallic line-terminals 13 and 14,respectively, which are located in opposite sides or IOO . rial, such asebonite.

portions 15 and 16 of an electric circuit. These terminals 13 and 14 arearranged oppositely, so as to constitute practically a fork orclamp-like device, which is capable of exerting a spring-pressure upon amember entered therein by virtue of the resiliency of the terminal 14,which is formed with a split end to compensate for any unevenness thatmay bein the surfaces of the contacts. These terminals 14 are secured inposition substantially parallel to the base upon the brackets 17 17,with which they are electrically connected.v The brackets 17 arefastened to the switch-base by screws 18 1S, and are each provided witha binding-screw 19, the ends of which engage the lines in the sockets20,which are formed suitably in the base 6, and for the purposes of theinvention the brackets and terminals 14 may be one piece. The terminals13, over which the terminals 14 project, are secured to the switch-baseby screws 2l, and are both provided with a binding-screw 22,v whichserves to bind the lines 1'5 16 in the respective sockets 20. Thus wheneach pair of terminals 13 and 14 are bridged across the circuit 15 16will be closed in the manner that is obvious. I

The terminals 13 and 14 are simultaneously bridged over by thebridging-contacts 10 10 being pushed, with their closed or arched partsforemost, in between the terminals when the switch-arm is turned in thedirection of the movements of the hands ot a clock. The free ends of thespring-terminals 14 are slightly upturned t-o aitord easy entrance otvthe bridgingecontacts.- It will be evident that when the contacts areentered between the terminals there will be a reciprocal springpressureexerted between such parts, by reason of the resiliency of the-terminals 14, and of the ends of the bridging-contacts 10. The constantrubbing of these parts against each other, in operating the switch, willkeep the metallicsurfaces bright and clean, and thereby afford goodelectrical connection, which will be rendered all the more reliable andclose because of the mutual pressure between the terminals and contacts.of the switch-arm are preferably located equal distances from thepivotal point thereof, and the eoactin g line-terminals are situatedcorrespondingly iii the path m'oved over by such contacts, and with thefree ends of the terminals 14 extending in opposite directions.

The switch-arm is shiftedback and forth on its pivot by the handle 23,the cross-head ol' which is made of suitable insulating mate- The shankof the handle is formed with an axial socket 24, and the foot 25 ot' thehandle is broadened out into a rectangular-shaped body, which is formedwith the curved slots 26 26, of equal curvatures struck from the axis ofthe handle as a center. The socket 24 of the handle receives the fixedstem 27, which projects from the yoke 28 in axial alignment with theaxis of the pivot of the switch-arm. rThis yoke- Thebridging-contactsthe handle a partialturn.

piece 28 connects the pins 29 29, which are fixed at equal distancesfrom the center of the switch-arm and extend parallel with the axis ofsuch pivot, and the heads of which are received by the slots 26 26,respectively, which are arranged diametrically opposite. One ot' thepins 29 is engaged by the free end of the spring 30, which has its otherend coiled about the bar 31, which is fixed in the switchbase. Thisspring is arranged, as will be Clearly understood from Figs. 1 and 2, soas to exert its force on the switch-arm 9 in a way that tends to turn iton its pivot in the direction opposite to that in which the hands of aclock move, except when the switch-arm is in full closed position, asshown in Fig. 2. In this latter position of the switch-arm the forceofthe spring 30 will be directed along the line of length ofthe arm, andconsequently on a dead-center, thereby in no wise tending to shift theswitch-arm when the latter is closed. Obviously the movement of theswitch-arm into the closed position tends to wind the spiral of thespring and to make it tense, so as to store up power by which theswitch-arm may be quickly opened after beingmoved ott the dead-center,as before described.v As soon, however, as the switch-arm is startedtobe opened and has moved nearly oit the terminals the full force of thespring will be exerted thereupon in such a way as to quickly shift thearm back against the stop l2 into open position. The spring-pressurebetween the bridging-contacts and the terminals will of course tend toclamp ,the switch-arm in confinement; but the power of the spring 30will overcome this as soon as the dead-center is passed. It will benoted that the contacts 10 and terminals 13 14 are designed to makequite an extended contact, and that it is not until the contacts areabout to move off the terminals that the spring 30 comes into play.

Vhen in opening the switch from the position shown in Fig. 2thehandle 23is grasped and slightly turned, the switch-arm is likewise moved, sincethe pins 29 are then at the ends of the slots 26, as shown in Fig. 1.The spring 30 now comes into play and tends to force the switch-arm openindependently of the handle, which it succeeds in doing when itovercomes the grip between the springterminals and.bridging-contacts.Under the action of the spring the switch-arm will be snapped open witha quick movement, in which the pins 29 are moved entirely through theslots 26 in the handle from the position shown in Fig. 1 to that shownin Fig. 2. Thus both sides of the circuit are opened simultaneously bythe automatic action of the switcharm, after the handle has been giventhe initial movement by the operator, so that the sudden andsimultaneous breaking of the circuit at each side thereof is insured andis wholly independent of the slow movement of the handle by theoperator, the switch being out of control of the operator after he givesThe simultaneous IIO closing of both sides or poles of the circuit andthe simultaneous and sharp quick opening thereof are desirable qualitiesin an electric switch, and especially so when used with a high-potentialcurrent, Where, on account of the sluggish movements of the switch-arm,the nonsimultaneous contact between the terminals and thebridgingcontacts would cause sparking, which would soon burn out thecontacts and impair the switch.

lhe operative parts of the switch are inclosed by the circularcup-shaped metal casing' 32, which is suitably fitted over theswitch-base (5, and is provided with a central opening` 'for the handle23 to pass through.

As the detail parts of the improved switch will admit ot' modifications,I Wish to be un derstood as not confining myself to the exactarrangement and constructions herein shown.

Having thus described my improvements in electric switches, what I claimas my invention, and desire to secure by Letters Patent, 1s

l. In an electric switch, the combination, with the pivoted switch-arm9, carrying the contacts and provided with a pin, such as the pin 29,the terminals engaged by said contacts, of the coil-spring' 30, madefast by one end and having` the other end bent to engage the said pin onthe switch-arm, the movement of which latter in one direction tends towind the spring` and make it tense, the said spring exerting itspressure upon the side of the pin remote from the pivotal center of thearm when the latter is in closed position, substantially as and for thepurpose set forth.

2. In an electric switch, the combination, with the switch-base 6, theswitch-arm 9, made of suitable insulatingmaterial and pivotedintermediate its ends, and provided with the springbridging-contacts l0l0, the line-terminals I3 I4, arranged oppositely and in correspondingly-located pairs and adapted to receive the bridging-contacts10, the spring 30, made fast by one end and connected by the other endto the switch-arm,the movement of which latter in one direction tends towind the spring and make it tense, the pins 29, fixed to the switch-arm,and the yoke 28, connecting` them, the stem 27, projecting' from theyoke in axial alignment with the axis of the pivot of the switch-arm,the key 23, formed with the socket 2i and havinpr the foot 25, formedwith the curved slots 26 26, all substantially as and for the purposeset forth.

In testimony whereof I have hereunto set my hand and seal, this 20th dayot August, 1888, in the presence of the two subscribing witnesses.

OSBORN P. LOOMIS. [Ls] Witnesses:

CHAs. A. PIERCE, RoBT. N. CLARK.

